1. Field of the Invention
This invention relates to machine tools.
More particularly, the present invention relates to machinery for forming a slot or groove into a workpiece.
In a further and more specific aspect, the instant invention concerns a machine especially adapted for cutting a groove for aligned joining of two or more members.
2. The Prior Art
Various types of frames, such as picture frames, typically include a plurality of elongate members which are abutted and joined, end-to-end, to form a parametric structure. A continuous rabbet extends about the inner edge of the normally flat backside for receiving the glass, picture or other display item. Usually the face side is ornamentally sculptured.
In order to insure continuity of the design carried upon the face side, a miter joint is employed at each corner of the structure. The abutting ends of the members are joined by various means such as mechanical fastening devices and adhesives. As will be readily recognized by those skilled in the art, fabrication of a frame structure in accordance with conventional practice requires specialized equipment and professional skills.
Consistent with the popularity of do-it-yourself projects, manufacturers have provided pre-cut frame members which are adapted to be assembled by persons of lesser skills. The members, which are commonly available in wood or metal, are joined by various means. Wood members, for example, are frequently united by a tongue and groove joint, the elements being carried by the respective mitered ends of the ajoining members. The prior art has also provided a shallow groove on the rear side of the members for receiving a conventional corner bracket which is affixed by screws.
Metal members are joined by various fastening devices. Exemplary is the specialty joining bracket such as the one distributed by Neilson Design, Townson, Mass., under the tradename Tabbed Corner.TM.. The device includes a planar, generally L-shaped element bearing a visual similarity to a conventional corner bracket. A set screw is carried in each of several threaded apertures extending through the legs of the element. The especially devised companion metal members each include a longitudinally extending T-slot, the narrow portion of which is open along the backside. During assembly, respective legs of the element are inserted into the slots of the members to be joined. THe screws are then rotated, as by a screw driver passing through the narrow portion of the slot, whereby the screws and the legs are brought into compression within the elements.
Corner brackets, either of conventional or specialty ilk, are exceedingly desirable for joining the members of a frame structure. The mechanical bond is conveniently and readily affected. Simultaneously, without exertion of extra care or effort, the angle between the adjacent members is spontaneously established as is the planarity of the structure. As an additional benefit, specialty brackets eliminate the necessity of penetrating the members with mechanical fastening means, such as screws.
Heretofore, however, corner brackets have proven to be less than entirely satisfactory in the fabrication of a wooden frame structure. Planar alignment of the members is established with respect to the surface of the groove against which the bracket is received. Metal members, usually fabricated by the extrusion process, are of uniform dimensions. Accordingly, all surfaces of the several frame members are brought into registry during assembly.
Wood, of the type normally used in frame structures, is not of uniform thickness. In accordance with industrial standards, deviation of approximately one-sixty fourth inch from nominal measurement is acceptable. Further, the prior art has taught that the bracket receiving groove, for purposes of machining, be located from the rear side of the member. Resultingly, the assembled frame structure includes a back side which is smooth and even, while the face surface may have variations as great as one-thirty second inch.
As previously noted, the face side of the frame structure is generally sculptured for aesthetic purposes. To accommodate individual considerations and to enhance and compliment selected display material, manufacturers have made available an almost limitless variety of designs and configurations. Yet, misalignment of the face side of the members, which are presented for viewing along with the framed display, materially subtracts from the intended affect.
Misalignment of members having relatively flat or nonornamental face surfaces can be partially corrected or obscured by the use of sandpaper. The result is generally less than perfection. On the other hand, ornamental surfaces are untouchable. Consequently, as will be readily appreciated by those skilled in the art, assembly of fine frame structures has largely remained the domain of highly skilled professionals.
It would be highly advantageous therefore to remedy the foregoing and other deficiencies inherent in the prior art.
Accordingly, it is an object of the present invention to provide improvements in the fabrication of frame structures.
Another object of the invention is the provision of improved means for assembling frame members.
And another object of the invention is to provide an improved machine for cutting bracket receiving grooves into the members of a frame structure.
Still another object of the instant invention is the provision of a machine for forming a groove at a predetermined location on the members.
Yet another object of the invention is to provide means for the automatic alignment of the face sides of the members during assembly of the frame structure.
Yet still another object of this invention is the provision of a machine having means for locating the frame members from the face side thereof.
Another object of the invention is to provide a machine having locating means which will accommodate variously contoured frame members.
And another object of the immediate invention is the provision of a machine especially adapted for the mass production of automatically aligning frame members.
Yet another object of the invention is the provide a machine which is relatively simple and easy to set up and use.
Still another object of the invention is the provision of a machine according to the foregoing which is comparatively uncomplicated inexpensive to manufacture.